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authorMika Westerberg <mika.westerberg@linux.intel.com>2016-09-20 15:30:51 +0300
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>2016-09-24 02:10:04 +0200
commit058dfc7670086edda8d34f0dbe93c596db5d4a6b (patch)
treea7f469b35b797f90a6cdc7c1c9859f62b36f4a14 /include/linux/acpi.h
parent3be7988674ab33565700a37b210f502563d932e6 (diff)
ACPI / watchdog: Add support for WDAT hardware watchdog
Starting from Intel Skylake the iTCO watchdog timer registers were moved to reside in the same register space with SMBus host controller. Not all needed registers are available though and we need to unhide P2SB (Primary to Sideband) device briefly to be able to read status of required NO_REBOOT bit. The i2c-i801.c SMBus driver used to handle this and creation of the iTCO watchdog platform device. Windows, on the other hand, does not use the iTCO watchdog hardware directly even if it is available. Instead it relies on ACPI Watchdog Action Table (WDAT) table to describe the watchdog hardware to the OS. This table contains necessary information about the the hardware and also set of actions which are executed by a driver as needed. This patch implements a new watchdog driver that takes advantage of the ACPI WDAT table. We split the functionality into two parts: first part enumerates the WDAT table and if found, populates resources and creates platform device for the actual driver. The second part is the driver itself. The reason for the split is that this way we can make the driver itself to be a module and loaded automatically if the WDAT table is found. Otherwise the module is not loaded. Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com> Reviewed-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to 'include/linux/acpi.h')
-rw-r--r--include/linux/acpi.h6
1 files changed, 6 insertions, 0 deletions
diff --git a/include/linux/acpi.h b/include/linux/acpi.h
index c5eaf2f80a4c..8ff6ca4a2639 100644
--- a/include/linux/acpi.h
+++ b/include/linux/acpi.h
@@ -1074,4 +1074,10 @@ void acpi_table_upgrade(void);
static inline void acpi_table_upgrade(void) { }
#endif
+#if defined(CONFIG_ACPI) && defined(CONFIG_ACPI_WATCHDOG)
+extern bool acpi_has_watchdog(void);
+#else
+static inline bool acpi_has_watchdog(void) { return false; }
+#endif
+
#endif /*_LINUX_ACPI_H*/